In the perturbative analysis, the unperturbed and perturbed effects are accounted by expressing [1]}, [2]}, [3]}, [4]}
\(\Omega ^{(0)} = \Omega ^{(0,0)} + \Omega ^{(1,0)} + \Omega ^{(2,0)} + \Omega ^{(3,0)} + \cdots \) 
